From a8f204894f8dd6d3259e892b6d61711ebf2505ab Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@users.mediawiki.org>
Date: Fri, 15 Dec 2006 00:10:33 +0000
Subject: [PATCH] Add replication-friendly background batch update mode. Rip
 out the ugly MySQL 4.0 mode and use the background mode for it, it should be
 compatible too. Add a little help text

---
 maintenance/initEditCount.php | 83 +++++++++++++++++++++++++++--------
 1 file changed, 64 insertions(+), 19 deletions(-)

diff --git a/maintenance/initEditCount.php b/maintenance/initEditCount.php
index a975f35616..9d165cfba5 100644
--- a/maintenance/initEditCount.php
+++ b/maintenance/initEditCount.php
@@ -2,35 +2,80 @@
 
 require_once "commandLine.inc";
 
-// @fixme: add replication-friendly batch mode
+if( isset( $options['help'] ) ) {
+	die( "Batch-recalculate user_editcount fields from the revision table.
+Options:
+  --quick        Force the update to be done in a single query.
+  --background   Force replication-friendly mode; may be inefficient but
+                 avoids locking tables or lagging slaves with large updates;
+                 calculates counts on a slave if possible.
 
+Background mode will be automatically used if the server is MySQL 4.0
+(which does not support subqueries) or if multiple servers are listed
+in \$wgDBservers, usually indicating a replication environment.
+
+");
+}
 $dbw = wfGetDB( DB_MASTER );
 $user = $dbw->tableName( 'user' );
 $revision = $dbw->tableName( 'revision' );
 
 $dbver = $dbw->getServerVersion();
-if( ($dbw instanceof DatabaseMySql && version_compare( $dbver, '4.1' ) < 0)
-	|| isset( $options['force-mysql4'] ) ) {
+
+// Autodetect mode...
+$backgroundMode = count( $wgDBservers ) > 1 ||
+	($dbw instanceof DatabaseMySql && version_compare( $dbver, '4.1' ) < 0);
+
+if( isset( $options['background'] ) ) {
+	$backgroundMode = true;
+} elseif( isset( $options['quick'] ) ) {
+	$backgroundMode = false;
+}
+
+if( $backgroundMode ) {
+	echo "Using replication-friendly background mode...\n";
 	
-	echo "Warning: MySQL $dbver; using hacky MySQL 4.0 compatibility query...\n";
-	$sql = "CREATE TEMPORARY TABLE temp_editcount (
-	  temp_user_id INT,
-	  temp_user_editcount INT
-	)";
-	$dbw->query( $sql );
+	$dbr = wfGetDB( DB_SLAVE );
+	$chunkSize = 100;
+	$lastUser = $dbr->selectField( 'user', 'MAX(user_id)', '', __FUNCTION__ );
 	
-	$sql = "INSERT INTO temp_editcount
-	  (temp_user_id, temp_user_editcount)
-	  SELECT rev_user, COUNT(rev_user)
-	    FROM $revision GROUP BY rev_user";
-	$dbw->query( $sql );
-
-	$sql = "UPDATE $user
-	  LEFT OUTER JOIN temp_editcount ON user_id=temp_user_id
-	  SET user_editcount=IF(temp_user_editcount IS NULL,0,temp_user_editcount)";
-	$dbw->query( $sql );
+	$start = microtime( true );
+	$migrated = 0;
+	for( $min = 0; $min <= $lastUser; $min += $chunkSize ) {
+		$max = $min + $chunkSize;
+		$result = $dbr->query(
+			"SELECT
+				user_id,
+				COUNT(rev_user) AS user_editcount
+			FROM $user
+			LEFT OUTER JOIN $revision ON user_id=rev_user
+			WHERE user_id > $min AND user_id <= $max
+			GROUP BY user_id",
+			__FUNCTION__ );
+		
+		while( $row = $dbr->fetchObject( $result ) ) {
+			$dbw->update( 'user',
+				array( 'user_editcount' => $row->user_editcount ),
+				array( 'user_id' => $row->user_id ),
+				__FUNCTION__ );
+			++$migrated;
+		}
+		$dbr->freeResult( $result );
+		
+		$delta = microtime( true ) - $start;
+		$rate = ($delta == 0.0) ? 0.0 : $migrated / $delta;
+		printf( "%s %d (%0.1f%%) done in %0.1f secs (%0.3f accounts/sec).\n",
+			$wgDBname,
+			$migrated,
+			min( $max, $lastUser ) / $lastUser * 100.0,
+			$delta,
+			$rate );
+		
+		wfWaitForSlaves( 10 );
+	}
 } else {
 	// Subselect should work on modern MySQLs etc
+	echo "Using single-query mode...\n";
 	$sql = "UPDATE $user SET user_editcount=(SELECT COUNT(*) FROM $revision WHERE rev_user=user_id)";
 	$dbw->query( $sql );
 }
-- 
2.20.1